Indirect Tax — Ad Valorem Tax

What this diagram shows

An ad valorem tax diagram shows how a percentage-based indirect tax (like VAT) affects market equilibrium by shifting the supply curve upward. Unlike specific taxes which add a fixed amount, ad valorem taxes create a proportionally larger tax burden as the product price increases. This type of government intervention reduces quantity traded while increasing the price paid by consumers and decreasing the price received by producers. Understanding this diagram is crucial for analyzing real-world policies like VAT, as it demonstrates how percentage-based taxes distribute the burden between consumers and producers.

Key points

• The supply curve shifts upward by the percentage rate of tax, creating a parallel shift that increases with price level
• Tax revenue equals the tax rate multiplied by quantity sold, shown as a rectangular area between the two supply curves
• Consumer burden and producer burden depend on price elasticity of demand and supply - more inelastic side bears greater burden
• Deadweight loss occurs due to reduced quantity traded, shown as a triangular area between the curves
• The tax wedge (difference between price paid and price received) increases proportionally with the product's price

Exam board notes

All major exam boards treat this diagram identically, requiring students to distinguish between ad valorem and specific taxes and analyze their different impacts on market outcomes. Some specifications emphasize calculating tax incidence more heavily than others.